UNRAVELLING THE MYSTERY OF CARAMEL
 
At the present time the New Zealand Cat Fancy and many of its breeders are caught up in the middle of a fascinating era of discovery of fresh knowledge. Cat breeding has never been so exciting and one particular area of interest to me is the intense interest centred around the caramel conundrum.

I have vivid recollections, as a young and green breeder in the early 1970s, trailing around the shows after the ‘old hands’ as they attempted to crack the puzzle of distinctive colour variation in dilute coloured cats.

As a Siamese breeder, it was within this breed that I have recollections of the frustration that was simmering at that time. A small group of breeders led by Peter Hovey (NZCF Chairman for several years) tried unsuccessfully to separate the blue and lilacpoint Siamese into two separate groups with particular importance on the division of the lilacs into ‘lilac’ and ‘frost’ points. It was not to be, and now and for many years past, breeders of numerous breeds the world over, have scratched their heads over dilute coloured kittens that just didn’t fit the bill, or the Standard of Points.
 
These strange coloured kittens appeared in a number of breeds, most specifically but not exclusively, the Siamese/Oriental/Balinese/Javanese group and the Birman group. Other breeds that have been notably involved in this strange equation are the Burmese/Mandalay group, British and Devon Rexes.
 
As long ago as the 1980s, feline geneticists proposed the scenario of a “Dilute Modifier” gene. This dominant gene was offered to us as the mechanism for disturbing the clumping of pigment within the hair shafts of dilute colours. The effect was labelled “Caramel”.
 
As time has elapsed people have lost sight of the original trail of events and have become confused about what caramel actually is. Caramel is not a colour but a modifier of an existing colour. Caramel can not stand alone, it has to have an actual colour to exist.
 
Let’s go back to the basics as it makes everything much clearer to understand. The colours that we do have in our cats are black, chocolate, cinnamon and red. These of course are what are known as dense colours because the genes controlling their optical appearance, cause the hair shafts to be packed to the gunnels with pigment. Absolutely stuffed to over-flowing. By comparison, cats who have two recessive diluting genes have hair shafts with air pockets in them. This is an effect produced because the pigment forms into clumps, called ‘klotting’ in some European papers on genetics. The air pockets have the effect of producing a reflection like light onto a mirror or a sheet of water, with the result that the dense pigment appears much lighter to our eyes. Black becomes blue, chocolate becomes lilac, cinnamon becomes fawn and red becomes cream.
 
Now is the point where the dilute modifying gene makes its entrance. This gene disrupts the clumping mechanism of the dilute gene. As the clumps are broken into and disturbed, so too is the reflective quality of each hair shaft. Instead of a clearly identified sparkling dilute colour we see a muddier version that has a brassy look in parts, and to totally confuse us, it is not stable. This muddy phenomenon is due to the diminished reflective qualities of the individual hair shafts.
 
In a nutshell, it is of the utmost importance that the Breeder is not misled by the word ‘dilute’, in the expression ‘dilute modifier’. Indeed this gene causes the dilute colours to appear darker than the shades outlined in our Standard of Points, not lighter.

The key factor to keep in mind when dealing with the dilute modifying gene is to remember that ‘Caramel’ is a pretty word (dreamed up by someone with an artistic flair in vocabulary), for describing a modification of existing dilute colours. Modifying is the operative word because Caramel can be likened to the inhibitor gene which produces our Smokes and Silvers as both merely change the way we see our colour range. The dilute modifier causes darkening while the inhibitor gene causes lightening of existing colours.
 
Just like the inhibitor gene, the dilute modifier is a non identity without a colour to work on. Without those colours there would be no silver, no caramel. This is why breeders of cats producing caramel tones are so emphatic that registries recognise the base colour of their cats. A similar analogy would be for all tabbies or all silvers to be registered just as that….tabbies or silver, with no descriptive colour identification.
 
So the moral of the story is, don’t despair when next you produce a kitten that changes its hue every time you cast your eyes on it. The poor thing is darker than its siblings, murkier that its mother and with its own lustrous appeal. Take a look at your pedigrees and start trying to put the jig-saw together. Keep in mind that because the dilute modifier is a dominant gene it can’t be carried as such. Dense coloured cats may have the gene but not display it, purely because of the physical make-up of their colour. Correctly coloured dilute cats can not carry it because in the famous words oft quoted….’if they did carry it, they would be it’.
 
In this age of technological wizardry we have so many more tools at our disposal. The Internet, chat forums filled with fascinating people with vastly different experiences …. and DNA testing.

What more could we ask for? I have supreme confidence that the riddle of the caramel cat, unlike the riddle of the great Sphinx will unfold in its entirety in the very near future. It will declare itself to be so simple we will wonder why we didn’t see it sooner. This for me will be a day of great celebration.


Avon Aspden